A power semiconductor device module includes an injection molded plastic housing. Within the housing is a DMB (Direct Metal Bonded)/semiconductor device assembly. The DMB/semiconductor device assembly includes a DMB structure. The DMB structure can either be a so-called DCB (Direct Copper Bonded) substrate or a so-called DAB (Direct Aluminum Bonded) substrate. In either case, the DMB structure is a multi-layer structure that includes an insulative but heat conductive center ceramic substrate layer. A planar bottom direct metal bonded metal layer is bonded to the bottom surface of the ceramic layer, and a planar top direct metal bonded metal layer is bonded to the top surface of the ceramic layer. In the case of the DMB being a DCB, these top and bottom metal layers are copper or a multi-layer structure involving copper. In the case of the DMB being a DAB, these top and bottom metal layers are aluminum or a multi-layer metal structure involving aluminum. The top metal layer is typically patterned into a plurality of islands of metal. Discrete semiconductor device dice and possibly other electronic parts are then surface mounted to the various islands on the top of the DMB structure. The various discrete semiconductor device dice and various portions of the DMB structure are then typically interconnected by bonding wires, both to each other, as well as to external connection terminals of the module, such that the overall wire bonded assembly is a desired power device circuit.
In one type of module, the bottom metal layer of the DMB forms a part of the outside surface of the module. This bottom metal layer of the DMB is supposed to be coupled to a heatsink. There is generally thermal grease or a phase change material disposed between the bottom of the DMB and the heatsink. Heat generated by the semiconductor device dice and other components within the module passes from the DMB, in some measure through the thermal grease or phase change material, and to the heatsink. An example of this type of module is the Y2-DCB module type available from IXYS Corporation, 1590 Buckeye Drive, Milpitas, Calif.
In a second type of module, the module includes a metal baseplate. The bottom metal layer of the DMB is mounted to the top of the metal baseplate. The bottom of the DMB does not form an outside surface of the module, but rather the bottom of the metal baseplate forms the outside surface of the module. The module is then mounted to a heatsink by placing an amount of thermal grease or a phase change material between the bottom of the metal baseplate and the heatsink. The module is pressed down onto the heatsink and is held in place by screws or bolts. Within the module, the DMB is either soldered to the top of the metal baseplate, or is pressed against the top of the metal baseplate with thermal grease or a phase change material disposed between the DMB and the metal baseplate. Heat generated by the semiconductor device dice and other components within the module passes down through the DMB, through the metal baseplate, and in some measure through the thermal grease or phase change material, and to the heatsink. An example of this type of module is the Y1-Cu baseplate module type available from IXYS Corporation, 1590 Buckeye Drive, Milpitas, Calif.